A few questions about home network

I was looking in the Home Network section of my Plusnet router and I don't understand a few things. Here's a screenshot at http://1drv.ms/Sy6Sp5

OK it shows the name of the network under the word Wireless. Then it shows what seem to be two devices connected wirelessly. One is - the Android phone (which has a little green tick), the other appears to be my computer, starting with 'pc.....' (though I can't see that name in the system information). And is actually connected by wire, though clicking the link shows connected to WLAN.

Then under the Ethernet bit - connected to port 2 is also the same numbered 'pc....'. Clicking shows it is connected to ethernet port 2, which is right as it is so. Then branching off there's robert-PC (with a green tick) which IS my computer name also showing connected to Ethernet port 2 (which it is).

Then another part connected branch is MediaServer (seems to be to do with Microsoft Media Player Sharing.

But I just wondered why the computer appeared to be connected two ways.

It may be the router saw the PC-b5c by wireless as some point, so listed but not ticked as active.

To add to Andrew's information, my recently-purchased HP Pavilion Tower has both Ethernet and WiFi, so shows up twice in the list below, under both Wireless and LAN, connected to a Brightbox 1.

CURRENTLY CONNECTED DEVICES
Name IP Address MAC Address Connection Type
HP-PC-2014-ALSD 192.168.1.14 (Mac Address) Wireless
CARTREF-PC 192.168.1.23 (Mac Address) Wireless
Unknown Device 192.168.1.116 (Mac Address) Wireless
Unknown Device 192.168.1.137 (Mac Address) LAN
HP-PC-2014-ALSD 192.168.1.250 (Mac Address) LAN

The PC supposedly has both 2.4 GHz and 5 GHz Wifi, although I have yet to prove that in practice.

I am waiting on FTTC being installed; and the received Brightbox 2 apparently has both WiFi Groups as well, so I am looking forward to observing what happens then.

CARTREF is my lady-wife's Laptop.
The Wireless Unknown Device is a WiFi-connected HP Printer.
The LAN Unknown-Device is a SAMKNOWS Whitebox Broadband Monitor.